1Division of Pharmacology, Department of Medicine, University of Cape Town Medical School K45, Old Main Building, Groote Schuur Hospital, Observatory, Cape Town 7925, South Africa2Department of Animal and Environmental Biology, Abia State University Uturu, PMB 2000, Abia State, Uturu, Nigeria

Received 19 June 2011; Revised 26 August 2011; Accepted 31 August 2011

Abstract

We investigated the antiplasmodial properties of crude extracts from Carica papaya leaves to trace the activity through bioassay-guided fractionation. The greatest antiplasmodial activity was observed in the ethyl acetate crude extract. C. papaya showed a high selectivity for P. falciparum against CHO cells with a selectivity index of 249.25 and 185.37 in the chloroquine-sensitive D10 and chloroquine-resistant DD2 strains, respectively. Carica papaya ethyl acetate extract was subjected to bioassay-guided fractionation to ascertain the most active fraction, which was purified and identified using high-pressure liquid chromatography (HPLC) and GC-MS (Gas chromatography-Mass spectrometry) methods. Linoleic and linolenic acids identified from the ethyl acetate fraction showed IC50 of 6.88 μg/ml and 3.58 μg/ml, respectively. The study demonstrated greater antiplasmodial activity of the crude ethyl acetate extract of Carica papaya leaves with an IC50 of μg/ml when compared to the activity of the fractions and isolated compounds.